The present invention relates generally to the field of molding elastomeric stock into the form of various mold cavities by transferring elastomeric stock from a transfer or injection unit into the mold cavities, and more particularly to apparatus for removing cured scrap from the sprues of the mold after each cavity-filling-and-compound-curing cycle.
In the field of injection or transfer molding, an injection unit or press is utilized for causing elastomeric stock to flow through various sprues or apertures formed in the mold and into corresponding mold cavities. During a subsequent period in which the stock cures in the mold cavities, the stock likewise cures in the mold sprues in the form of upstanding, plug-like elements extending outwardly of the sprues.
These plug-like elements of cured scrap must be removed from the sprues before the mold can be again cycled. Removal of the cured scrap from the sprues is often a time consuming chore which is conventionally done manually by the use of various brushes or blowers and the like, or simply by hand. Thus, there is a margin of human error associated with this procedure. The failure to effectively remove all of the cured scrap from the sprues may leave the latter at least partially blocked, thereby preventing elastomeric stock from penetrating the sprues and filling the mold cavities on a subsequent injection or transfer cycle. Moreover, the injection or transfer pressure may force the cured elements of sprue scrap through the sprues and into the mold cavities, thereby mixing the sprue scrap with elastomeric stock that is yet to be cured in the mold cavities. Upon curing of this already partially cured mixture, there results the formation of elastomeric products in the mold cavities which are non-homogeneous and, thus, faulty.